This shouldn't come as a huge surprise. Jonathan Riddell, lead developer of the Kubuntu project and the only person paid by Canonical to work on the KDE variant of the popular distribution, has announced that after the 12.04 release, Canonical will no longer be funding him, effectively putting Kubuntu on the same level as other Ubuntu variants like Xubuntu.

Yeah, I wouldn't imagine that Unity is easy to port to non-Ubuntu distros (including Debian). My point is that future shells will likely be more portable because of Unity (including its negatives).

The "shell war" will be messy in the short term because it splits a relatively thick monolithic layer into two layers along a fault line that until now had never really erupted as a de facto interface surface in the FOSS desktop stack.

But in the long run, I think we're better off with a discrete shell layer, and mailing list threads like the one above suggest that there is plenty of motivation to make this shell layer work for the FOSS community.